<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            display: flex;
            width: 90%;
            height: 200px;
            background-color: orange;
            justify-content: space-around;
        }
        div span{
            width: 200px;
            height: 150px;
            background-color: red;
            margin-right: 10px;
        }
    </style>
</head>

<body>
<!-- flex布局意为弹性盒子布局，对移动端布局很适用，但是对PC端的支持不那么友好 -->

</body>
    <div>
        <span></span>
        <span></span>
        <span></span>
    </div>
</html>